1. Field of the Invention
The invention relates to document processing, document imaging, and magnetic ink character recognition. The invention further relates to hand-operated document readers/imagers, and to methods and systems for providing speed feedback in a hand-operated document reader/imager.
2. Background Art
A typical document processing system includes a feeder and a separator in the document-feeding portion of the system, and a series of roller pairs or belts in the document-transporting portion of the system. In the feeding portion of the system, the feeder acts with the separator to feed documents singly, in order, from a stack. In the transporting portion of the system, the roller pairs and/or belts convey the documents, one at a time, past other processing devices such as readers, printers, and sorters that perform operations on the documents. The feeder is typically a feed wheel, but may take other forms. The separator may be a wheel, but also may take other forms such as a belt. Further, the components in the transporting portion of the system may take a variety of forms.
In addition to large document processing systems that handle stacks of documents, smaller systems also exist. These smaller document processing systems may handle smaller stacks of documents, or may even handle single documents, fed one at a time. There are also hand-operated document readers/imagers.
Banks, credit unions, and other financial institutions use document processing systems to regularly process checks, deposit slips, and other types of bank documents in order to execute financial transactions efficiently. Document processing systems have therefore become quite prevalent in the industry. Typically, information is printed on these documents in magnetic ink which can be read both by the human eye and a computer. This form of printing is read by a process called magnetic ink character recognition (MICR). As part of the recognition process, a MICR magnetic read head is used to read the information printed on the document.
Conventional approaches to MICR reading and recognition generally involve determining peak position information for a waveform generated by a single gap magnetic read head. This peak information typically includes information regarding the amount of time between the peaks of each character. Knowledge of the velocity of the document (and thus, the velocity of the characters which are printed on the document) allows this time information to be converted into distance information, which can be compared to the MICR character peak profiles as contained in ANS X9.100-20-2006 (formerly published as X9.27) “Print and Test Specifications for Magnetic Ink Printing (MICR)” as published by Accredited Standards Committee X9, Inc., Annapolis, Md., United States. Based on the design of the standard E-13B character set, in order that a MICR reader reliably read with a high correct character read rate and with a very low substitution rate, the document velocity must be precisely known during reading or otherwise be speed-controlled so that it does not vary.
These conventional approaches are acceptable when the velocity of the document is either known or can be controlled. In fact, conventional approaches to MICR typically involve rather complex schemes for controlling the velocity of the document or attempting to measure its velocity at different times as the document moves past the MICR read head. There has also been an approach to MICR reading and recognition that utilizes a dual gap read head to eliminate the need for precise knowledge or control of the document velocity.
In a hand-operated document reader/imager, the document is placed on a base and the MICR/image device is moved over the document from right to left, which is the traditional direction of larger document readers. During this movement, the MICR characters are recognized and the front image of the document is captured.
A hand-operated document reader/imager requires a method of determining the position, and thus the speed, of the MICR and image sensors due to the variable speed nature of the manual operation. Existing solutions use optical encoders to provide this position feedback. Optical encoders are typically attached directly to the shaft of a wheel that moves along the document being scanned, or are connected to this shaft through a series of gears. These existing solutions have several shortcomings. Dust can build up in the optical encoder and cause position feedback errors. To avoid dust buildup, optical encoders need to be cleaned regularly or sealed in a dust-free enclosure, which adds cost. Also, the wheel must be in contact with the document, which may cause the document to move in such a way as to reduce the quality of the scan result. In addition, the wheel may slip, which will cause position feedback errors.
For the foregoing reasons, there is a need for an improved method and system for providing speed feedback in a hand-operated document reader/imager.